Work Package 4

Pelagic food-web structure, trophic interactions and the role of fish for overall trophic transfer efficiency in the Humboldt Current upwelling system off Peru

Work Package Leaders

Description

The Humboldt Current systems sustains the production of the largest commercial fishery worldwide, the Peruvian anchoveta (Engraulis ringens). Current knowledge still has not revealed why this eastern boundary upwelling system (EBUS) has such a high trophic transfer efficiency compared to other EBUS. Moreover, the impact of projected climate-driven changes in upwelling strength on trophic transfer efficiency is unknown. In WP4, we will investigate the food web characteristics and major trophic pathways to address these questions. This research will be conducted during an oceanographic cruise and a mesocosm experiment, in close collaboration with partners at the Instituto del Mar de Peru (IMARPE).

Specific objectives in WP4 include:

  • Conduct process studies on the abundance, distribution and vital rates (feeding, nutritional condition and growth) of fish across oceanographic discontinuities (mesoscale eddies, filaments, OMZ) and upwelling intensities in the HUS;
  • Evaluate the relationship between upwelling intensity, trophic transfer and export production (special emphasis on anchovy and mesopelagic fishes);
  • Quantify rates of growth, nutritional condition and survival of young anchovy during a largescale mesocosm experiment simulating changes in upwelling intensity
  • Contribute parameterizations necessary for trophic modelling within an individual-based model for anchovy larvae and an OSMOSE web model (WP6).